1. Field of the Invention
The present invention relates to a slitting method of a battery separator-use resin film object that is less susceptible to defects such as holes and tearing at the time of slitting, and a battery separator-use resin film object obtained by such a method.
2. Prior Art
Conventionally, a film object made of resin (film, sheet, etc.) has been widely used as a battery separator-use material. An explanation will be briefly given of one example of manufacturing processes of this resin-made film object: the processes include a kneading process, a rolling process, a first slitting process, a drawing process and a second slitting process, and these processes are successively carried out in this order. In the kneading process, pellets of a resin composition are manufactured, and rolled into a predetermined film object through the rolling process. This film object is once slit into two parts in the width direction, and rolled and extended in the width direction. This rolling and extending process allows fine pores in the order of sub-micron to be formed therein so that a porous film object is obtained. Then, this porous film object is slit so as to have a desired width dimension in the second slitting process.